Orogeniczne żyłowe złoża złota i ich rozsypiska a największe światowe gorączki złota w drugiej połowie XIX wieku w Ameryce i Australii
Pourquoi ce travail est dans la base
Une base qui oublie comment elle a trouvé un travail ne peut pas être vérifiée. Voici les voies qui ont admis celui-ci.
Notice bibliographique
Résumé
Orogenic lode gold deposits and placers and the world’s largest Gold Rushes in the second half of 19 th century in America and Australia. A b s t r a c t . The paper presents geological, ore-mineralogical and economic characteristics of the goldfields in the Western USA (California and Yukon) and Australia (Bendigo-Ballart and Kalgoorlie regions). Moreover, common geological features of these areas, which were the place of modern Gold Rushes from the second half of 19 th c. to the beginning of 20 th c. are also described. Thanks to discovery of gold, these inhabited areas became the land of promise for millions of people and gold production contributed to economy of the fast growing nations. The first period of Gold Rushes began in California (USA) and Bendigo-Ballart region in Victoria (Australia) in 1848 and 1851, respectively. Placer gold was discovered first in Cenozoic alluvial sediments and subsequently in auriferous quartz lodes, which were the source of detrital gold. The detrital sediments appeared extremely rich in gold nuggets. The biggest nuggets, ca. 65.2 and 24.5 kg in weight, have been found in Bendigo and California, respectively. Placer gold production during the Gold Rush in California from 1848 to 1864 is estimated at ca. 1300 Mg Au. Since 1850, prospectors begun to discover numerous gold-bearing quartz veins (Mother Lode system) along the Sierra Nevada in California. These auriferous lodes gave over 1100 Mg of gold. In Bendigo-Ballart goldfields about 480 Mg of gold was extracted from placers and 260 Mg gold – from from auriferous quartz veins in the years 1851–1861. The second period of modern Gold Rushes took place again in America (Yukon) in 1896 and in the Western Australia (Kalgoorlie) in 1893. In Yukon, gold was mainly extracted from Cenozoic river’s gravels (> 311 Mg) and in Kargoorlie—mainly from auriferous quartz-carbonate lodes. Some of goldfields with auriferous lodes discovered in 19 th c. are still in production. Best example is here the Kargoorlie deposit that became recently the 3 rd largest world producer of gold (> 1600 Mg Au). Gold production from lodes in California, Bendigo-Ballart and Kalgoorlie is roughly estimated at > 4000 Mg. Gold-bearing lodes formed as results of migration of fluids of various origin and gold precipitation in the upper crust within post-collisional tectonic settings. These lodes belong to orogenic type of gold deposits hosted by greenstone schist belts in metamorphic terranes of various age. Primary gold is bound mostly by auriferous sulphides—arsenopyrite and pyrite and as native gold which infills fractures in quartz and breccias. In California, Yukon and Victoria, rich placers were formed in the Cenozoic during exhumation of metamorphic terranes hosting auriferous gold lodes.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,003 | 0,002 |
| Méta-épidémiologie (sens strict) | 0,003 | 0,002 |
| Méta-épidémiologie (sens large) | 0,003 | 0,001 |
| Bibliométrie | 0,001 | 0,004 |
| Études des sciences et des technologies | 0,002 | 0,001 |
| Communication savante | 0,001 | 0,002 |
| Science ouverte | 0,007 | 0,003 |
| Intégrité de la recherche | 0,002 | 0,003 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,003 | 0,004 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découle